Improvement in refining iron and steel



N. B. HATCH.

Refining Iron and Steel.

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Patented Dec. 17,1872.

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UNITED STATES To all ichom it may concern: Be it known that I, NATHANIEL BLANoH- ARD HATCH, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and Improved Mode of Retining Metals, of which the following is a specis ytcation: Y s 1. Myimprovement relates to the agitation and 'purification of molten iron or other metals inlosed within a stationary retort or crucible, or on a furnace-hearth, by forcin g through such molten metal streams of intensely-heated deoxygenated or carbonized atmospheric air, ob- 1 *tained .by previously passing atmospheric air K through abody of re or carbon iu a hi ghl y heated or incandescent state; and in order to accoms r plish this I arrange, immediately under or in Y close proximity to the hearth, crucible, or retort a close chamber, in which I burn the carburet- Vf ing material, and'into which, at ditierentpoints,

' above, below, or adjacent to the earbureting material, a series of air-pipes provides the means of supplyingrair in the desired quantities and at ther desired points. This chamber consti' tutes a holder as well as a heater, so as to introduced directly into the molten metal. My improvement consists in the features of construction and combination hereinafter set forth and claimed.

' y The means by which Iput my invention into practice will be readily understood by the following description, taken in connection with the accompanying drawing, wherein- X Figure l represents a transverse vertical section of the refining apparatus; Fig. 2, a l transverse section on the dotted lines asa.

- To carry my invention into operation, I take v a strong cylindrical metallic casing, A, and secure it in a. perpendicular position on a circular iron bed-plate, D. This casing is provided with an opening, s, therein, near its bottom, leading into that part intended for the ash-pit R, and a similar opening, T, on a ver- Y ticalline a short distance above, so as to open into the fire-box N. Each of these openings j are to be closed by a tightly-fitting door, o, held in place by a yoke, g, and screw t, or any other mechanicalcontrivance that will answer the end. On the opposite side of this cylinder A is erected an air-receiver, B, which, by

' `keep the gas at a, high temperature till it is' PATENT OFFICE.

{NATHANIEL E. HATCH, or riTTsBune, rEnNsYLvANL/i, Assienon To HIM. sELE Ann riTTsBUEo. BOLT COMPANY, or sAMETLAcE.

l' IMPROVEMENT IN REFININ'G IRON AND STEEL.

Specification forming part of Letters Patent No. 133,937, dated December 17, 1872.

means of a large supply-pipe, X, is placed in communication with a powerful blast-engine; and by a series of smaller branch pipes, e e ke e, in connection with the interior of the cylinder A, the lowermost branch pipe leading directly into the ash-pit R, and the others above the grate K, at different heights, into the fire-box N. Each of these branch pipes is provided with a valve or cock, n, for regulating the admission of air either above, below, or through the lire. Above the grate and opening into the fire-box is arranged an inclined chute, C, furnished at its top with a hopper, l?, having a tightly-fitting lid, on, and tilting bottom a, so that carbonaceous fuel may be fed as desired into the re-box` N in such a manner as to prevent the 'escape of either air or gas in that direction.' The cylinderA is to belined with clay or tire-brick, anda dome-shaped arch, G, con'- structed of. similar refractory material, above the fire-box N, which arch has several small vertical openings l l Z, made through it. Just at the spring of the arch is ataphole,V, similar to those used in ordinary melting-furnaces; and near the top of the cylinder is a small outlet or waste hole, W. The cylinder Ais also provided with a loosely-fitting cap, J, lined with fire-clay, and arranged so as to be raised or lowered in the cylinderA by means of a chain, L, attached thereto.

Operation.

The several-parts of thisapparatus being constructed as 'shown and set, forth, a lire is to be kindled on thegrate K and the doors o o closed perfectly tight, when a blast of airA proportion to the quantity of metal poured in,

rushes with great force through the fire, and the several small openings, ZZ l, in the arch G,

(prevents the molten metal from falling,)

and drives through the liquid mass, producing therein a violent ebullition, raising the impurities and foreign matter, as gas and scoria, to the surface, the gaseous matter escaping directly into the atmosphere, and the scoria re- .charged with carbon previousto its entering the molten metal; otherwise such oxygen would search out the native carbon and utterly destroy it. To deoxygenate such air as may constitute the blast, it is caused to pass through a body of re, by which the affinity of its oXygen for highly-heated carbon is supplied or neutralized, and thereby converted into a carbonio-oxide gas, which, bein g indifferent to the carbon in the metal as it passes through, attacks only the phosphorus, sulphur, silicium, and other impurities, which are volatilized and pass oftl as gas, or are driven to the surface in the condition of scoria, that may be allowed to flow off or be removed by mechadical means, leaving the metal in a highly-carbureted state. Should it be found requisite to discharge the whole or a portion of this carbon, the same may be accomplished by causing the blast to pass partially or entirely above the fire, by which it will enter the metal in varying conditions, or may be sent in as simple heated atinospheric air, carrying with it its oxygen, which, uniting With the carbon in the metal, consumes it, speedily bringing the metal to a decarbonized and partially-oxidized condition. To reinstate, or rather replace, by other carbon the carbon so consumed, the blastis thrown once more under and throifgh the body of lire, Where its oxygen, taking up its equivalent of carbon, is converted into a carbonio-oxide gas, as hereinbefore stated, which, in passing upward through the molten metal, gives up a.

portion of its carbon to the metallic oxides until they are completely saturated or satisfied, bringing the metal once'more to a carbonized condition, and, if iron, giving it the quality of steel. As the metal becomes refined its density and gravity are increased, the heavier portion sinking to the bottom of the crucible, where it may be drawn off from time to time through the tap-hole V and run into in gotmolds, or otherwise, as the exigency of the case may require.

Cl'aims.

I claim- 1. A close chamber, N, for treating air, pre` paratory to utilizing the same in the purification of molten metals, such chamber being supplied with carbureting material, and having leading into it a series of air-pipes at diiferent points relative to the carbureting material, whereby the air may be prepared for admission to the molten metal more-or less oompletely deo'Xygenated and carbureted, at pleasure, substantially as set forth.

2. The carbureting-chamber and series of' air-pipes of the last claim, arranged in combination with a furnace-hearth, retort, or crucible so as to discharge into the molten metal the air or gas at the same temperature and in the same condition in which 1t leaves the deoxygenating and carbureting material, substantiall y as set forth.

N. B. HATCH.

Witnesses:

FRANCIS ToRRENcn, GoRNELroUs CALLro. 

